In general, a memory module such as the SRAM is contained in a semiconductor integrated circuit device such as a system LSI.
Some of these memory modules mentioned above are provided with a power control section for reducing power consumption by cutting off the power during a period when a circuit operation is not needed. This power control section is provided, for example, in each divided memory mat.
The power control section consists of a memory mat, an input-output circuit, a control circuit, a plurality of MOS (Metal Oxide Semiconductor) transistors provided between the power supply voltages supplied to peripheral circuits such as a word driver, a predecoder circuit and the like, and a power control circuit for controlling the on and off of these MOS transistors.
The power control circuit cuts off the power supply voltage supplied to the memory mat, the input-output circuit, and the peripheral circuits by turning off the MOS transistors at the standby time of the semiconductor integrated circuit device.